Signs and symptoms that your dog may have gotten into some poison are vomiting, acting drunk, rapid heartbeat, depression, lack of appetite "not wanting to eat" and Diarrhea.
If you think your dog has been poisoned or has gotten into some poison you should take your dog to the vet.
In some places there are emergency vet hospitals open 24 hours a day that you don't need an appointment to show up at.
If possible get your dog to the vet as soon as possible if you suspect dog poisoning.